[DELETED]Causes of Abnormal Menstrual Bleeding

A normal menstrual period lasts from two to seven days and fits into a cycle that restarts approximately every 21 days. Most women experience abnormal bleeding at some point in their lives.

A normal menstrual period lasts from two to seven days and fits into a cycle that restarts approximately every 21 days.  Most women experience abnormal bleeding at some point in their lives.

Abnormal bleeding includes spotting (light bleeding between periods), heavy bleeding between periods, unusually long or short periods, missed periods and unusually light or heavy periods.  Bleeding at times when you shouldn’t, like during pregnancy or after menopause, also fit this classification.

For the most part, abnormal uterine bleeding is perfectly natural.  Sometimes, though, it can signal something more.


The most common reason for irregular uterine bleeding is pregnancy.  Spotting or very light bleeding may occur with no real significance, but you should always check with your doctor if you’re bleeding while pregnant.

Heavier bleeding, particularly during the first trimester, may be a sign of miscarriage.  You doctor can determine if this is the case with a pregnancy test or a sonogram.

If you have had a miscarriage, a D&C might be necessary.  This type of bleeding may also indicate ectopic pregnancy (when the fetus starts to develop outside the womb), which requires immediate surgery.

Heavy bleeding after the first trimester can indicate problems like placenta previa (when the placenta covers some or all of the opening to the cervix).  In this case, it is likely that you will notice a problem before bleeding occurs but it important to note that, if bleeding is too heavy, the baby may have to be delivered early.

Hormonal Imbalance

Another common reason for abnormal menstrual bleeding is having too much or too little of certain hormones.  This often occurs during adolescence, when hormone levels fluctuate.

Birth control pills are frequently used to control these fluctuations.  Before the onset of menopause, this type of instability is also quite common.

Hormone imbalances can also rise from dramatic changes in weight, vigorous exercise, excessive stress or as a side-effect of some medications.  A hormone imbalance can eventually lead to endometrial hyperplasia, a condition caused when the endometrium is flooded with estrogen.

The result is that the endometrium, which lines the uterus and is shed monthly with your period, becomes too thick.  Without treatment, this can become cancer.

IUD and Birth Control Pills

In intrauterine device (IUD) can cause abnormal bleeding by irritating the uterine lining.  The bleeding is usually accompanied by cramping.

If you had no problems before inserting the IUD, it is a good sign that this is the cause.  Have the IUD removed and, if it was the cause, your periods should return to normal.

Birth control pills can cause irregular bleeding in a few ways.  When you first start taking the pill, spotting, unusually long periods or missed periods are all common.

If this persists, though, it may mean that the particular pill is not right for you body and your doctor will likely switch you to a different type.  Missing pills can also cause surprise periods or spotting.

Taking your pill daily at a specific time will greatly diminish your chances of unexpected bleeding. 

Polycystic Ovarian Syndrome (PCOS)

Also called Stein-Leventhal syndrome, Polycystic Ovarian Syndrome occurs when you don’t ovulate regularly.  This hormonal problem comes with a number of symptoms including: acne, obesity and excessive hair growth.

Any of these symptoms may not occur with PCOS but irregular or no menstrual periods always accompany this condition.  Women with PCOS face higher risks of other conditions, including heart disease, diabetes and endometrial cancer, so it is important to see your doctor if you suspect you have it.

There are a variety of tests your doctor can perform to confirm PCOS.  Birth control pills can be used to maintain regular periods and protect against uterine cancer.

Other treatments, ensuring four periods per year, can be used for women who don’t want birth control. 

Infection of Pelvic Organs

If your period comes with pain or foul-smelling greenish discharge you may have an infection of a pelvic organ, such as your uterus, cervix or ovaries.  Bleeding would commonly follow sex or douching.

These infections are often caused by sexually transmitted diseases.  One such condition is pelvic inflammatory disease (PID), usually a sexually transmitted disease but sometimes contracted after gynecological procedures such as childbirth, is an infection that causes inflammation of the uterus, fallopian tubes or ovaries.

Once diagnosed, PID can be treated with antibiotics.  For all of these infections, once your doctor determines which STD has caused the infection, you can be treated for that specific condition.

Uterine Fibroids

Fibroid tumors are non-cancerous tumors that grow in the uterine muscle.  They usually affect women in their 30s or 40s.

Most common among black women, they are also fairly common among white women, but extremely rare in Asian women.  In addition to abnormally heavy periods and bleeding between periods, kidney problems and pressure in the lower abdomen are common symptoms.

Although the exact cause is unknown, they can be effectively treated in a number of ways.  Surgical treatments including myomectomy, uterine balloon therapy and hysterectomy, are possibilities.

Some medications, including oral contraceptives, may be enough to deal with the tumors.  In some cases, no action is taken as, with menopause, the tumors usually disappear on their own.

Other Causes

Other possible reasons for abnormal menstrual bleeding include polyps, small growths that develop in the cervix or uterus.  Their causes are unclear, but are related to an excess of estrogen, which may be the result of an infection, hormone treatment or some types of ovarian tumors.

Cervical polyps can be treated by having the growths removed in an outpatient procedure and then taking antibiotics.  Endometrial polyps are more often dealt with via hysteroscopy and D&C.

The growths are typically benign but, to be certain, they would be evaluated for cancer once they are removed.  Bleeding disorders like hemophilia may also result in abnormal bleeding.

Additionally, abnormal development of the organs, cancer of the uterus or cervix, sexual abuse, an object in the vagina, extreme emotional stress or other diseases like diabetes, can cause irregular menstrual bleeding. 


About the Author

An American living in Prague, Whitney Arana holds a Bachelor of Arts in English language and literature from Davidson College. Currently, she works as a teacher of advanced business and exam-prep English plus conversational Spanish. She contributes regularly to both Czech and American publications on topics including health, literature, food, and travel.